1 # SPDX-License-Identifier: GPL-2.0-only 1 # SPDX-License-Identifier: GPL-2.0-only
2 config HAVE_GCC_PLUGINS 2 config HAVE_GCC_PLUGINS
3 bool 3 bool
4 help 4 help
5 An arch should select this symbol if 5 An arch should select this symbol if it supports building with
6 GCC plugins. 6 GCC plugins.
7 7
8 menuconfig GCC_PLUGINS 8 menuconfig GCC_PLUGINS
9 bool "GCC plugins" 9 bool "GCC plugins"
10 depends on HAVE_GCC_PLUGINS 10 depends on HAVE_GCC_PLUGINS
11 depends on CC_IS_GCC !! 11 depends on CC_IS_GCC && GCC_VERSION >= 40800
12 depends on $(success,test -e $(shell,$ !! 12 depends on $(success,$(srctree)/scripts/gcc-plugin.sh $(CC))
13 default y 13 default y
14 help 14 help
15 GCC plugins are loadable modules tha 15 GCC plugins are loadable modules that provide extra features to the
16 compiler. They are useful for runtim 16 compiler. They are useful for runtime instrumentation and static analysis.
17 17
18 See Documentation/kbuild/gcc-plugins 18 See Documentation/kbuild/gcc-plugins.rst for details.
19 19
20 if GCC_PLUGINS 20 if GCC_PLUGINS
21 21
>> 22 config GCC_PLUGIN_CYC_COMPLEXITY
>> 23 bool "Compute the cyclomatic complexity of a function" if EXPERT
>> 24 depends on !COMPILE_TEST # too noisy
>> 25 help
>> 26 The complexity M of a function's control flow graph is defined as:
>> 27 M = E - N + 2P
>> 28 where
>> 29
>> 30 E = the number of edges
>> 31 N = the number of nodes
>> 32 P = the number of connected components (exit nodes).
>> 33
>> 34 Enabling this plugin reports the complexity to stderr during the
>> 35 build. It mainly serves as a simple example of how to create a
>> 36 gcc plugin for the kernel.
>> 37
22 config GCC_PLUGIN_SANCOV 38 config GCC_PLUGIN_SANCOV
23 bool 39 bool
24 # Plugin can be removed once the kerne <<
25 depends on !CC_HAS_SANCOV_TRACE_PC <<
26 help 40 help
27 This plugin inserts a __sanitizer_co 41 This plugin inserts a __sanitizer_cov_trace_pc() call at the start of
28 basic blocks. It supports all gcc ve 42 basic blocks. It supports all gcc versions with plugin support (from
29 gcc-4.5 on). It is based on the comm 43 gcc-4.5 on). It is based on the commit "Add fuzzing coverage support"
30 by Dmitry Vyukov <dvyukov@google.com> 44 by Dmitry Vyukov <dvyukov@google.com>.
31 45
32 config GCC_PLUGIN_LATENT_ENTROPY 46 config GCC_PLUGIN_LATENT_ENTROPY
33 bool "Generate some entropy during boo 47 bool "Generate some entropy during boot and runtime"
34 help 48 help
35 By saying Y here the kernel will ins 49 By saying Y here the kernel will instrument some kernel code to
36 extract some entropy from both origi 50 extract some entropy from both original and artificially created
37 program state. This will help espec 51 program state. This will help especially embedded systems where
38 there is little 'natural' source of 52 there is little 'natural' source of entropy normally. The cost
39 is some slowdown of the boot process 53 is some slowdown of the boot process (about 0.5%) and fork and
40 irq processing. 54 irq processing.
41 55
42 Note that entropy extracted this way 56 Note that entropy extracted this way is not cryptographically
43 secure! 57 secure!
44 58
45 This plugin was ported from grsecuri 59 This plugin was ported from grsecurity/PaX. More information at:
46 * https://grsecurity.net/ 60 * https://grsecurity.net/
47 * https://pax.grsecurity.net/ 61 * https://pax.grsecurity.net/
>> 62
>> 63 config GCC_PLUGIN_RANDSTRUCT
>> 64 bool "Randomize layout of sensitive kernel structures"
>> 65 select MODVERSIONS if MODULES
>> 66 help
>> 67 If you say Y here, the layouts of structures that are entirely
>> 68 function pointers (and have not been manually annotated with
>> 69 __no_randomize_layout), or structures that have been explicitly
>> 70 marked with __randomize_layout, will be randomized at compile-time.
>> 71 This can introduce the requirement of an additional information
>> 72 exposure vulnerability for exploits targeting these structure
>> 73 types.
>> 74
>> 75 Enabling this feature will introduce some performance impact,
>> 76 slightly increase memory usage, and prevent the use of forensic
>> 77 tools like Volatility against the system (unless the kernel
>> 78 source tree isn't cleaned after kernel installation).
>> 79
>> 80 The seed used for compilation is located at
>> 81 scripts/gcc-plgins/randomize_layout_seed.h. It remains after
>> 82 a make clean to allow for external modules to be compiled with
>> 83 the existing seed and will be removed by a make mrproper or
>> 84 make distclean.
>> 85
>> 86 Note that the implementation requires gcc 4.7 or newer.
>> 87
>> 88 This plugin was ported from grsecurity/PaX. More information at:
>> 89 * https://grsecurity.net/
>> 90 * https://pax.grsecurity.net/
>> 91
>> 92 config GCC_PLUGIN_RANDSTRUCT_PERFORMANCE
>> 93 bool "Use cacheline-aware structure randomization"
>> 94 depends on GCC_PLUGIN_RANDSTRUCT
>> 95 depends on !COMPILE_TEST # do not reduce test coverage
>> 96 help
>> 97 If you say Y here, the RANDSTRUCT randomization will make a
>> 98 best effort at restricting randomization to cacheline-sized
>> 99 groups of elements. It will further not randomize bitfields
>> 100 in structures. This reduces the performance hit of RANDSTRUCT
>> 101 at the cost of weakened randomization.
48 102
49 config GCC_PLUGIN_ARM_SSP_PER_TASK 103 config GCC_PLUGIN_ARM_SSP_PER_TASK
50 bool 104 bool
51 depends on GCC_PLUGINS && ARM 105 depends on GCC_PLUGINS && ARM
52 106
53 endif 107 endif
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